Furnace



Aug. 14, 1923. v L46537 J. A. FLEMINGS ET AL FURNACE Fild Dec. 14, 1918 s Sheets-Sheet 1 Aug. 14, 1923. 7 11,465,537

' J. A. FLEMINGS ET AL FURNACE Fild Dec. 14, 1918 3 Sheets-Sheet 2 Au* .14,19 3. "f M65037.

J. A. FLEMINGS ET AL FURNACE Patented Aug. 14, 1923.

earne STTE area" JOHN A. FLEMINGS, OF SHARON, MASSACHUSETTS, AND ERNEST B. PR'IEBE, OF WIL- KINSBURG, PENNSYLVANIA, ASSIGNOR-S TO B. F. STURTEVANT COMPANY, OF HYDE PARK, Ii'IASSACHUSETTS, 1A CORFOEATION OF MASSACHUSETTS.

FURNACE.

Application filed December 14, 1918'. Serial No. 266,767.

'Massachusetts, and at Wilkinsbur in the county of Allegheny and State .of ennsyl- Vania, respectively, have invented certain new and useful Improvements in Furnaces;

and we do hereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to which itappertains to make and use the same.

The invention relates to furnaces of the underfeed type, in which the fuel is'fed into the furnace below the fuel bed and below the openings for the air supply, whereby the fuel is first coked .andthe volatile matter liberated and then consumed upon passing through the burning layer of fuel.

In furnaces embodying the preferred form of the invention the fuel is fed to the combustion chamber through one or more underfeed retorts extending from the front toward the rear longitudinally of the fire box. Overfeed grates are arranged along the side walls of the retorts, which are sta tionary immediately adjacent the retorts' but movable at their outer portions to provide means for a progressive advance of'the fuel bed toward the bridge wall over the in termediate overfeed grates, and to and over a stationary auxiliary grate at the rear of the retorts. An adjustable ash plate is provided at the rear of the auxiliary grate, and receives the ash or refuse from the grate surfaces. The discharge of the ash from the ash plate is facilitated by a series of" clearing bars, adapted to reciprocate vertically adjacent the bridge wall,ithe movements thereof acting to clear the face of the bridge wall and to-disintegrate the ash and permit a definite amount to be released fromthe ash plate. a

For adetailed illustration of one form of apparatus embodying the invention, reference may be had to the following description and to the accompanying drawings forming a part thereof, in which Figure 1 is a. plan view, partly in section, showing the relative arrangement of the retorts, grates and feeding mechanism; Fig. 2 is a vertical sectional View taken substantially on the line A--A, Fig. 1; Fig. 3 is a similar iectional view taken substantially on the me transverse sectional view taken substantially on the line C-C, Fig. 2.

In the drawings the numeral 1 indicates the front wall of a furnace of any wellknown r preferred type, and 2 the bridge wall thereof. Between these walls, and in the fire box or combustion chamber, are located the various grates and retorts comprising the automatic stoker for the continuous feeding of fuel to the boiler. In the present form of the invention there are a plurality of retorts 3, having reciprocating bottoms 4. The fresh fuel is forced into these'retorts through the flaring openings 5 by means of the well-known plunger-s 6, as clearly shown in Fig. 2. The bottoms 4 of the retorts 3 are reciprocated by being connected with the operating means for the plungers through the intermediary of the bar 7, the lever 8 and the rock shaft 9, which is oscillated by an arm 10 connected with an operating bar 11 adapted to engage an abutment or angle iron 12 carried by the plunger 6.

Referring to Figs. 1 and 2, it will be seen that at the sides of the retortsS are stationary blocks 13 having openings 14 for supplying air to coke the fresh fuel prior to its passage into the burning layer thereof. These blocks also constitute stationary grate sections extending longitudinally of the sides of the retorts. Beyond the stationary grate sections adjacent the walls of the retorts, and between the same and the side walls of the combustion chamber, are reciprocating grate sections in the form of grate bars which comp-rise supports 15 upon which are secured grate blocks provided 'with air passages 16, as indicated in section in Figs. 3 and 4. These supports are caused to reciprocate in a manner similar to that of the bottoms of the retorts, by being con nected with the rock shaft through the lever 17 and the bar '18.

Just below the inner ends of the overfeed grate bars are auxiliary stationary grate bars 19 also having air openings as indicated in section in Figs. 2 and 3. Between the auxiliary grate 19 and the bridge wall 2 is an adjustable ash plate 20 which is moved for- Ward or back to regulate the opening for the BB, Fig. 1; and Fig. 4 is a vertical from the ash pit through the heads and be tween the heads and bridge walls. All or some only of these bars may be caused to reciprocate along the front of the bridge wall 2 by means of racks 26 and pinions 27, which latter are carried on the transverse shaft 28. This shaft is oscillated by means of suitable connections (not shown) with the feeding mechanism for the fuel, above mentioned.

The space 29 is separated from the space 30 by the partition 81 and the supports 32, or other suitable means.

Air under pressure, for a forced draft, is supplied to the chamber 29 below the retorts and ntermediate overfced grates, while the auxiliary stationary grate 19 is preferably supplied by air under natural draft from the ash pit 30.

A justment of the amount of movement of the bottoms of the retorts and of the reciprocating grates is obtained by the filling pieces .33 on the ends of the bars 7 and 18, and whose removal or introduction allows more or less lost motion between the pin and slot which connects the bars to the levers S and 17 respectively whereby the movements of said bars are decreased or increased.

By the above features of construction a minimum weight of movable parts is attained, while at the same time the fuel is fed positively and continuously at points where positive motion is most desirable.

The vertically reciprocating clearing bars have somewhat the action of a slicing bar,

and keep the surface of the bridge wall free grate bars between the stationary grate bars at the sides of the retorts permits a substan tial increase in the effective surfaces of the overfeed grates to which the coked fuel is delivered from the retorts, and at the same time ensures a substantially continuous and uniform movement of the entire fuel bed, thus increasing the efliciency of the stoker and rendering it particularly applicable to large installations. The intermediate sta tionary sections of the grates also ensure a more positive retention of the fuel during the outward strokes of the movable sections and of the bottoms of the retorts.

lVhat is claimed is L l. A furnace, having, in combination with a fire box, an underfeed retort having air conducting and discharging means at the sides and above the bottom thereof and forming fixed grates at the sides of said retort, said retort having a movable bottom, mov able grate sections at the sides of the fixed grates, and means for simultaneously reciprocating said grate sections and the bottom of said retort.

2. A furnace, having, in combination with a fire box, underfeed retorts having air conducting and discharging means at the sides and above the bottoms thereof'and forming grates at the sides of said retorts, said retorts having movable bottoms, aplurality of intermediate movable grate sections between the retorts, and means for reciprocating adjacent intermediate movable sections in opposite directions and simultaneously with the movement of the bottoms of the respective retorts.

3. A furnace, having, in combination with a fire box, underfeed retorts, grates having movable portions for advancing the fuel and provided with air conducting and discharging means, an auxiliary stationary grate at the rear of said retorts and said grates, and an ash plate adapted to receive the fuel from said auxiliary grate.

4. A furnace, having, in combination with a fire box, underfeed retorts, grates having relatively movable and fixed portions and provided with air conducting and discharge means, an auxiliary fixed grate at the rear of said retorts and said former grates, and

former grates and air under natural draft to said auxiliary grate.

JOHN A. FLEMINGSL ERNEST B. PRIEBE. 

